問題詳情

149. In a shipment of 20 packages, 7 packages are damaged. The packages are randomly inspected, one at a time, without replacement, until the fourth damaged package is discovered.

Calculate the probability that exactly 12 packages are inspected.
(A) 0.079
(B) 0.119
(C) 0.237
(D) 0.243
(E) 0.358

參考答案

答案:B

統計:A:0,B:0,C:0,D:0,E:0

難度:計算中